Thoughts on Corewar...

Thoughts on Corewar is John Metcalf's Redcode programming blog, hosted at http://impomatic.blogspot.com. Since John's blog was last reviewed, both the name and design have changed.

The standard template has gone and the sidebar now contains a selection of useful rss feeds, including the latest posts from rec.games.corewar and the most recent additions to the infinite nano and tiny hills.

The most interesting recent posts have been about Semaphores in Redcode, which provide a means of implementing mutual exclusing in Corewar.

What I liked:

• Covers advanced programming topics
• The feeds make it easy to keep up-to-date

Room for improvement:

• More comments on the code would be handy

Miz's Corewar Page

A few days ago Mizcu moved his webpage to http://users.evtek.fi/~mikaos/corewar/, so now seems like an ideal opportunity to take a closer look.

The highlight of Mizcu's site is Monowire's story, the tale of a beginner's warrior.  Mizcu details the development of his oneshot from a beginner warrior to king of the KOTH.org '94nop hill.

Also in the Redcode section, Mizcu publishes some of his Corewar projects, including a generic table scan, Stoney the second and Lady Imperactive. Huffpaper includes an interesting variation to the standard silk concept.

Finally, there's an article about decoys which Mizcu is working on.  This covers the basics, active decoys, invisibility and will eventually include decoy makers.

What I liked:

• Monowire's story

Room for improvement:

• A few comments would make the code easier to understand

Will Varfar's Corewar Page

Will Varfar has a webpage devoted to Corewar at http://redcoder.sourceforge.net and shares some of his experiences implementing and testing Redcode simulators and evolvers.

Will's Which MARS report gives a thorough examination of different simulators, including some observations on their inner workings. The report concentrates on 6 open source MARS. It would be interesting to see the closed source simulators included in the comparison.

Species is Will's Redcode evolver, which attempts to improve on past evolvers with the introduction of species and chromosomes. Source code and a Windows .exe are available to download.

Some interesting statistics are published on Will's page. Will has gathered data about the frequency of opcode execution during a round robin of over 400k battles. Taking this one step further, graphs have been generated showing how the opcode frequency changes during a battle.

This data has been used to automatically divide the warriors into groups based on their execution fingerprint. It might be interesting to compare the results to those of Joonas's self organising maps.

Finally, there are a couple of article in which Will discusses the development of his entries for Neo's Mini Challenge #3 and Redcoder's Frenzy round 9.

What I liked:

• In my opinion, Will has the most visually attractive Corewar site
• 100% original content

Room for improvement:

• the 3d graph of Optimax benchmark stats is a bit tricky to interpret
  

Łukasz Grabuń's Book of Stones

Łukasz Grabuń has a small Corewar site at http://grabun.com/corewar.  Apart from a selection of useful links, Łukasz's site contains the Book of Stones which he describes as "a modest continuation to the second chapter of Steven Morell's book".

The first chapter has an analysis of Carbonite by Ian Sutton.  After describing Carbonite's bombing run and the switch to a clear, the interaction with an opponent D-Clear is examined in detail. Unfortunately, the advantage of the remote bomb and using add.ab {0,}0 in preference to add.ab -1,-1 are not mentioned.

Behemot by Michal Janeczek is discussed in the second (and final) chapter.  The article begins by introducing the airBag and incendiary bomb techniques before moving on to Behemot's inner workings and interaction with dat bombers.

What I liked:

• The Book of Stones

Room for improvement:

• The chapter about Carbonite doesn't mention a couple of important points

Tales from the Digital Wilderness

Tales from the Digital Wilderness is John Metcalf's Redcode programming blog, hosted at http://impomatic.blogspot.com.  Emphasis is given to implementing real algorithms in Redcode such as sorting and seaching.

John uses a standard Blogger template, with a post archive and a selection of useful Corewar links in the sidebar.  Usually there are 3 to 4 posts per month.

There are two Corewar related posts.  Parallel Processes describes a useful pMARS macro and An Improved '88 Quick-scanner shows how Paul Kline's technique can be used to create a 48 instruction '88 qscan which scans 36 locations.  The remainder of the blog is devoted to algorithms.

Some posts I found particularly interesting are Comb sort, Stooge sort and Gnome sort which I hadn't previously heard of.  Apart from sorting, there are implementations of seaching and number theory algorithms.  A post comparing the performance of the different techniques would be an interesting addition.

What I liked:

• A unique concept
• The code is well written

Room for improvement:

• For the more complex code, a detailed description would be nice
• A few comments would make the code easier to understand

Philip Thorne's Corewar Introduction

Philip Thorne's Corewar Introduction can be found at http://home.pipeline.com/~corewar and has been reporting the latest tournament news since 2002.  The homepage has a handy selection of links for Corewar beginners.

What really make's Phil's site stand out is the unique content.  There are two useful tools, RSS feeds for the KOTH hills and a Redcode syntax definition for VIM.  The RSS feeds are updated daily.

Phil's Stone Analysis article has a thorough examination of 13 stones, comparing everything from speed and coverage to the type of core-clear.  Unfortunately, I didn't understand all of the figures in the table - a key would be helpful.

Finally, Phil has published a selection of warriors.  The layout here is almost perfect!  The warriors are presented in an interactive tree structure and the warrior files are displayed with syntax highlighting.

What I liked:

• The Stone Analysis article
• The presentation of warriors

Room for improvement:

• A key to help interpret the Stone Analysis table

Neo's World of Corewar

Germán Labarga completely overhauled his website a few months back with a new URL, new design and updated content. The new location is http://labarga.atspace.com. The new layout is clutter free and easy to navigate.

Neo used to pose a programming challenge in Redcode every couple of weeks, and the results from the Mini Challenges are hosted here. There's also a selection of Neo's published warriors. This section could be improved a little by including some short comments.

The highlight of the site has to be the article documenting P-Key's Development. P-Key is an adaptive switcher which won the Smart Switching tournament round.

What I liked:

• The results from the Mini Challenges
• The article about P-Key

Room for improvement:

• Some brief comments on the warriors page would be nice
• The tools page needs more links (it currently has only one)